This invention relates in general to metal casting and in particular to an improved method of separating a gate remnant from a casting.
As used herein, metal casting is a method of delivering molten metal to a die or sand mold to form a casting or castings. A gating system, which is used to bring molten metal to a mold cavity, includes an arrangement of sprues, risers or feeders and gates or in-gates. The sprue is the part of the gating system that connects the molten metal to the risers. The riser is the part of the gating system that forms the reservoir of molten metal necessary to compensate for losses due to shrinkage as the metal solidifies and is located between the sprues and the in-gates. The in-gate is the part of the gating system that connects the riser to the mold cavity. The casting is the product that results from the solidification of molten metal in the die or mold. The gate remnant is the portion of the gating system that is separated from the casting by a degating process.
A known method of separating the gate remnant from the casting includes saw cutting through the in-gates. In the case of a sand mold, the sand from the sand casting process can produce excessive wear on the saw blades, requiring frequent and costly replacement of the saw blades. The saw cutting process also produces undesirable metal chips. Additionally, the in-gates are often difficult to access with a saw blade. It would therefore be desirable to provide an improved method of separating a gate remnant from any casting.